As discussed in U.S. Pat. Nos. 4,175,810 and 4,097,101, incorporated herein by reference and assigned to the assignee hereof, electrical interconnection boards, typically referred to as printed circuit, printed wiring or panel boards, normally have mounted thereto a plurality of electronic components such as dual-in-line (DIL) electronic packages which may be integrated circuit packages for other types of electronic components formed with any number of leads. The boards are provided with holes, commonly called "thru holes" or "via holes." The boards are also provided either with printed circuit paths or conductive voltage planes or both. In some prior art devices, leads of electronic components are inserted into plated-through holes, which holes are electrically connected to various printed circuit paths on one or both sides of the board. An electronic device lead is typically then inserted through one of the plated-through holes and is individually soldered or collectively wave soldered so that the hole is filled with solder to permanently mount the component to the board and make positive electrical interconnection with the printed circuit paths.
As discussed in U.S. Pat. No. 4,175,810, it is often desired to employ the concept of plugability, that is, to be able to plug the leads of a component into a board for whatever purposes are desired and then to remove it and plug another component into the board. This, of course, is not possible with the previously discussed method of mounting components to the board because the component leads are soldered thereto. In the past it is known to provide two part socket sleeve assemblies which are mounted in non-plated holes in panel boards wherein one of the sleeves has a lead receiving socket and the other end normally provides a solder tail or wire wrapping pin. See for example, U.S. Pat. No. 3,784,965. The solder tail and wire wrapping pins project for some appreciable distance beyond the component side of the board and the lead receiving socket end of the sleeve normally projects a short distance beyond the other side of the board.
Another commonly used alternative which permits plugability is an insulated socket with contacts mounted thereon. These contacts have extending pins to engage holes in the board and have sockets to receive the lead to the component. The extending pins are normally soldered to the board, such sockets have typically been of DIL configuration, represented by U.S. Pat. No. 3,989,331 and U.S. Pat. No. Des. 210,829.
With respect to the slotted prior art pins which resemble needles having centrally located eyes, such as Feed Thru and Feed to Post Amp Model 117820, not only are these pins not compliant in the sense used herein, they do not contact the entire plated-through hole but rather provide at most two points of contact within the hole.
The aforementioned patents assigned to the assignee hereof are primarily designed to limit the height of the interconnect system vis-a-vis the top surface of the printed circuit board. These connectors include a pin assembly having a fixed or rigid diameter in which the pin is forced into a plated-through hole, with an annular groove being provided circumferentially about the pin into which solder from the plating is squeezed as the pin is inserted into the hole. The proximal end of the pin is slotted such that a lead inserted through a central channel in the pin is gripped by the teeth left by the slotting. The major portion of the pin, and that which contacts the interior solder coated walls, is rigid in both U.S. Pat. Nos. 4,175,810 and 4,097,101, thereby precluding the use of these pins for boards having holes of different diameter. Morever, although the pins are extremely useful for low Z-plane applications, the insertion force is sometimes excessive so that occasionally damage occurs to the plated-through hole. Additionally, when utilizing pins of fixed diameter, tolerances must be held tighter with respect to the hole size and with respect to the thickness of the plating so that the pins can be utilized.